Method of making magnetic materials.



UNITED STATES,

ROBERT A. HADFIELD, OF SHEFFI PATENT OFFICE.

ELD, ENGLAND.

METHOD OF MAKING MAGNETIC MATERIALS.-

Specification of Letters Patent.

Patented Nov. 27, 1906.

Application filed July 5,1906. Serial No. 324,896.

To all whom it may concern: Be it known that I, ROBERT ABBOTT HAD- FIELD, a subject of the King of Great Britain, residing 'at Sheffield, England, have invented a certain new and useful Improvement in Methods of Making Magnetic Materials, of which the following is "a specification. In United States Letters Patent No. 767,110, granted to me August 9, 1904, I have described and claimed a method of making ma etic material, which consists in rolling an a loy of iron combined with other elements (more particularly silicon, aluminiurn, or phosphorus) into thin sheets and then subjecting said rolled sheets to a heat treatment, whereby said sheets are first heated to a temperature below the Ineltingpoint, al'-, lowed to cool, reheated to a temperature above that first employed, and then fin'ally cooled. As the magnetic material referred to (and especial] the alloy or alloys above mentioned) is co d-short, the rolling or forging of the alloy into thin sheets as set forth in my patent aforesaid necessarily implies a preliminary'heating of said alloy to a high tem erature in order to enable it to be thus' mec anically treated.

My resent invention differs from that claime in my Letters Patent aforesald m that instead of first subjecting the rolled or wroughtthin sheetr to a temperature below that subse uentl employed I subject it to one hi her t an t at subsequently employed.

Thus first heat the alloy to, say, 9509 centi ggade, cool, reheat to 750 centigrade, and

all cool.

1. The herein-described method of producing a'ma etic material of hi h ermeability and low ysteresis action which consists in alloying a magnetic substance with silicon, reducing the alloy to a thin body, heating such thin body to a temperature below its melting-point, allowing it to cool, reheatin it to a temperature below that first employe and again allowing it to cool.

2. The herein-described method of producing a magnetic material of hi h permeability and low hysteresis action, w 'ch consists in alloying a magnetic substance with silicon, heating the mass and working the same into a sheet, heating such sheet to a temperature below the meltin -point of the material and allowing it to coo reheating said sheet to a? temperature below that first employed andagain allowing it to cool.

In witness whereof I have signed my name hereto in the presence of two witnesses.

fROBERT A. HADFIELD:

-. Witnesses: I V 1 HENRY E. DIXON, FRANK HUTsoN. 

